This invention is directed to clear or transluscent liquid detergents that are unbuilt or built with water-soluble builders. Such detergents generally comprise 1 to 60% surfactants; up to 5% foam control agents; up to 10% water-soluble detergent builders; 0.1 to 2% of an active agent which can provide anti-redeposition, viscosity-modifying, and improved cleaning performance functions; and remainder to 100% of water and other ingredients. In a preferred embodiment, the active agent is a water-soluble or water-dispersible polymer of an alpha-beta ethylenically unsaturated lightly crosslinked lower aliphatic carboxylic acid having molecular weight in the range of about one-half million to 5 million, measured at room temperature. Such detergents are particularly effective on cotton and cotton/polyester fabrics.
As already noted, the active agent that is used in liquid laundry detergent compositions disclosed herein can provide the functions of soil anti-redeposition, viscosity modification, and improved cleaning performance. This agent has been used in detergent compositions in the past and is identified in the prior art as neutralized crosslinked polyacrylate polymer, as modified polyacrylic thickening agent, and as sodium polyacrylate. The prior art discloses the use of the active agent at a level of about 0.1 to 2% by weight of total composition.
British patent 2,079,305 describes built liquid enzymatic detergents containing, inter alia, an enzyme, a polyol, boric acid, and a neutralized crosslinked polyacrylate polymer. The polyacrylate polymer is described as being water-soluble polymer of acrylic acid crosslinked with not more than 10% of a cross-linking agent containing a vinyl group. Specific examples of the polyacrylate polymer noted in this patent include Carbopol.RTM. 934, 940 and 941, products of The B. F. Goodrich Company, assignee of the invention claimed herein. Amount of the polyacrylate polymer is disclosed as 0.1 to 2% by weight of the total detergent composition. The use of a polyol, boric acid, and a polyacrylate polymer in liquid enzymatic detergents results in stable aqueous, built enzymatic liquid detergents which have satisfactory enzyme stability, especially at higher pH, as well as storage stability.
The unbuilt liquid laundry detergents disclosed herein are patentable over the British patent since the patent does not teach nor suggest the use of a polyacrylate polymer in conjunction with unbuilt liquid enzymatic detergents. This is based on disclosure in lines 21-26 of the patent where it is stated that the use of a polyol and boric acid in certain ratio has been suggested in the prior art. Although this patent does teach the use of a polyacrylate polymer in built liquid detergents in conjunction with a polyol and boric acid, this patent discloses at middle of column 2, on page 2 that all kinds of builders can also be used. Although any builder appears suitable for use in the liquid enzyme detergents disclosed by the British patents, only water-soluble builders are suitable in the liquid laundry detergents described herein. It is also important to note that this patent discloses at bottom of column 2, on page 2 that other conventional materials can also be present in the liquid enzymatic detergents. Many different conventional materials are listed, including soil suspending agents. Polyacrylate polymers were not known as soil-suspending agents at time of the filing of the patent application which matured into the British patent. The prior art, at that time, recognized the use of carboxymethyl cellulose and other materials disclosed at top of column 10 of U.S. Pat. No. 4,092,273, as known soil suspending agents. Carboxymethyl cellulose is effective on cotton but ineffective on cotton/polyester blends. It is believed that the use of polyacrylate polymers, and other suitable polymers disclosed herein, as soil suspending agents was discovered by applicants and is disclosed for the first time. Therefore, the use of polyacrylate polymers, and other cognate materials disclosed herein, as suspending agents, would eliminate the use of the conventional soil suspending agents. Furthermore, the invention disclosed herein does not rely on the interaction of a polyol, boric acid and a polyacrylate to obtain a liquid detergent having satisfactory enzyme stability as well as satisfactory physical storage stability.
U.S. Pat. No. 4,147,650 describes slurry detergents comprising alkali metal hydroxides and/or silicates, condensed phosophates, sodium hypochlorite, and sodium polyacrylate. This patent asserts that slurry detergents are more advantageous than granular or liquid detergents since the granular detergents are subject to caking and the liquid detergents are limited in their strength by the solubility of their ingredients. This patent also asserts that the disclosed slurry detergent makes it possible to use more complex phosphates and alkaline ingredients since a slurry does not require a true solution. A slurry, as described by this patent, is a mass of semi-fluid ingredients of relatively homogenous nature. Sodium polyacrylate acts synergistically with sodium tripolyphosphate to form a homogeneous suspension in slurry form, thus facilitating uniform and complete dispersion. As long as no more than 30% of sodium tripolyphosphate and 5% of sodium tripolyphosphate is used, a satisfactory slurry is formed. If more is used, the mass becomes too viscous or may solidify. Minimum amount of tripolyphosphate is 5% and that for polyacrylate is 1%, on dry weight basis. Generally, amount of the polyacrylate in the detergent composition can be in the range of 1 to 10% by weight, on anhydrous basis.
The liquid detergent compositions disclosed herein are patentable over U.S. Pat. No. 4,147,650 because the ingredients thereof are wholly soluble therein and the liquid detergent compositions are, for that reason, clear or transluscent, in absence of pigment. As is apparent from the above discussion, the ingredients in the slurry detergent compositions are not wholly soluble therein by definition, and thereby, are not clear or transluscent. Furthermore, although sodium tripolyphosphate can be present in liquid detergents described herein, it can be present up to its solubility limit of about 10% in water. Therefore, since sodium tripolyphosphate can be absent from the liquid detergents disclosed herein, the synergism between it and sodium polyacrylate, relied on by U.S. Pat. No. 4,147,650, would also be absent, indicating a different kind of detergent.
U.S. Pat. No. 4,215,004 is also directed to slurry detergent compositions. These detergents are heavy duty, built detergents containing an alkali metal hydroxide, detergents, sodium polyacrylate, a modified polyacrylic acid, and water insoluble aluminosilicate ion exchange material and/or complex phosphates, as well as other conventional additives.
The liquid detergent compositions disclosed herein are patentable over U.S. Pat. No. 4,215,004 for the same reasons presented in connection with U.S. Pat. No. 4,147,650. Principally, the basic distinction is that inherent in a liquid detergent as compared to a slurry detergent.
U.S. Pat. Nos. 4,092,273 and 4,368,147 relate to liquid detergents and both emanate from the same parent application. The detergents disclosed in these patents have viscosity of 40 to 120 cps at 24.degree. C., contain nonionic surfactants, an alkanol, a viscosity prevention agent, and water. In one patent, the viscosity control agent is a water soluble salt of a dicarboxylic acid whereas in the other patent, the viscosity control agent is sodium or potassium formate in conjunction with the alkanol. These two patents are noted only as being illustrative of liquid detergent compositions.